<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
</head>
<body>
<style type="text/css">
	div{
		width: 200px;
		height: 200px;
		background: #000;
		border-radius: 0 50% 50% 50%;
		transform: rotate(45deg);
		margin: 200px auto;
	}
	span{
		display: block;
		width: 160px;
		height: 160px;
		background: #fff;
		border-radius: 0 50% 50% 50%;
	}
</style>
	<div><span></span></div>
	<script type="text/javascript">
		function show(n1){
			return function(n2){
				return n1+n2;
			}
		}
		var num1=show(3);
		var num2=show(4);
		console.log(num1(5));
		console.log(num2(6));
	</script>
</body>
</html>